scientists are concerned about the accumulation of toxins like DDT and mercury in systems of predators. why are large predators, like owls and eagles, the most threatened by these toxins?
2006-10-15 12:50:27 · 7 answers · asked by bill 1 in Environment
They are at the top of the food chain. If a bug eats something with a pesticide on it, then a small bird eats a lot of those bugs and picks up a large dose of the pesticide, and finally a predator eats a lot of those birds so it gets the grand total of all that pesticide with its meal.
2006-10-15 12:54:40 · answer #1 · answered by Rich Z 7 · 2⤊ 1⤋
The way it happened in England was that DDT was sprayed on crops then eaten by insects, the insects were eaten by pigeons and then the pigeons were eaten by Peregrines. But rather than the falcons receiving a weaker dose of DDT, the chemical got stronger as it worked up the food chain, this almost resulted in the extinction of peregrines in Britain, and if it hadn't have been for falconers this extinction would have happened.
Basically because raptors are in smaller numbers than their prey it affects them first.
2006-10-18 06:28:11 · answer #2 · answered by Aquila 4 · 0⤊ 0⤋
Biomagnification. Owls and eagles are at the top of the foodchain. Concentrations of toxins are magnified as you move up the foodchain, because there are less individuals as you climb higher up the foodchain.
2006-10-15 19:58:03 · answer #3 · answered by VTNomad 4 · 2⤊ 0⤋
Because they live solely on the flesh of animals who ingest the toxins and store them in their organs. It concentrates the effect of the poison.
2006-10-15 19:59:20 · answer #4 · answered by Buffy Summers 6 · 1⤊ 1⤋
All the answers are correct, but the first one is how it really impacts these animals. Their eggs can get so thin that sitting on them breaks the eggs.
2006-10-15 20:35:36 · answer #5 · answered by Alan J 3 · 1⤊ 1⤋
The DDT makes their eggshells very thin and brittle which lowers their reproduction rate.
2006-10-15 19:54:10 · answer #6 · answered by Anonymous · 2⤊ 2⤋
why is everyone getting cancer
cuz of the white man
2006-10-16 08:41:43 · answer #7 · answered by native,pride 5 · 0⤊ 0⤋